package facade;

/**
 * @Author liangliangzhao
 * @data 2023/4/14 11:26
 */

public class Screen {
    private static Screen instance = new Screen();

    public static Screen getInstance(){
        return instance;
    }

    public void up(){
        System.out.println(" Screen up ");
    }


    public void down(){
        System.out.println(" Screen down ");
    }
}
